>>46471099True, that works. Although the problem there is
1) some games like FRLG don't even allow you to do this because you have to unlock non-kanto pokemon in the post-game
2) trade pokemon gain boosted XP, so it's a lot easier to get too overpowered without even intending it
I still think a NG+ mode would be better. Start back over at your home town, but all the trainers have new teams leveled up, starting at where the E4's pokemon were leveled, and scaling up from there, with the E4 being level 100